Electric-furnace heating unit



Jan. 12 1926 1,569,415

J. c. WOODSON ELECTRIC FURNACE HEATING UNIT Filed Jan. 25, 1924WITNESSES! OR MW 555 C: [4600 50 LVM Patented Jan. 12, 1926.

UNITED STATES v 1,569,415 PATENT .OFFICE.

JAMES C. WOODSON, OF EAST PITTSBURGH, EENNSYLVANIA, ASSIGNOR TO WESTING-HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA.

ELECTRIC-FURNACE HEATING UNIT.

Application filed January 25, 1924. Serial No. 688,377.

To all whom it may concern: Be it known that-I, JAMES C. WOODSON, a

citizen' of the United States, and a resident of East Pittsburgh, in thecounty ofvAllegheny and State of Pennsylvania, have invented a new anduseful Im rovement in ity heating unit that shall have both terminalslocated at each end thereof.

Another object of my invention is to pro vide a heating-unit of theabove indicated character that shall have a unitary terminal andsupporting structure.

In practicing my invention, '1 provide a resistor member of relativelyheavy wire or rod, preformed to comprise. a plurality ofparallel-extending, return bent straight portions, one-half of saidportions being folded,

back over and lying adjacent to the other half thereof. A plurality ofsets of refractory members of electric-insulating material are locatedon metal rods extending through a perforation therein and have aplurality of pockets in one surface thereofto' receive the rounded endsof the resistor member.

.Metal side bars, substantially coextensive with the metal rods, extendclosely adjacent to-the outer grooved surface of the refractory membersand interfit with the rods'adjacent to the ends thereof.- End barsoperatively engage the ends of the rods and of the side bars ,toconstitute therewith the skeleton supporting frame.

The rods extending through the perforated refractory members have therespective ends of the resistor member connected thereto and' therebyprovide terminal memhers at each end ofthe unit.

. vIn the single sheet of drawings;

rel is a view, inside elevation, of

an e ectricheating unit embodying my in.- vention, and

Fig'. 2 is a view, partially end elevation and partially section, takenon the line IIII of Fig. 1.

relatively heavy resistor member 12 that is rality of straight,substantially parallel-extending return-bent portions. The resistormember 12, preferably of a suitable resistor material, such as nichrome,is preformed to such shape that all of the straight returnbent portionslie in a single plane. .One half of the straight return-bent portions isfolded over against the other half thereof and is located in a planespaced from and cosely adjacent to the plane of the first half. Thisbending may be'done by twisting one or twoadjacent straight portions orby bending one 'of the rounded end portions. A p urality of refractorysupporting members 13, of electric-insulatinglmaterial, are eachprovided with a plurality of sets of spaced pockets 14 therein, thepockets extending longitudinally of the members 13 in the inner facethereof. The rounded portions of the reistor member 12 fit into therespective pockets 14, the spacing of the resi'stor member and of thepockets beingsuch as to permit of this relatlve location.

- The length of the return-bent portions of the resistor member 12 isslightly less than the distance between the bottom portions of therespective pockets 14 in the spacedapart sets of refractory members 13to permit of rounded.

' The rod 16 and the respective members 13 i of refractory materiallocated thereon are therefore interfitting and any lateral turningmovement of the me bers'13 on the rod 16 is efie'ctively precludiiii bysuch interfit- .m 9

i The outer longitudinal surfaces of each of themembers 13 is providedwith a rela tively *wide groove or depression 17 and a bar 18 ofrelativelythin, fiat metal, is lov oated therein to further strengthenthe An electric heating unit 11 comprises a.

structure and to still further prevent relative movement of the members13 on the bar 16 and to hold the members 13 thereon,

even if any of the members 13 should break conductors (not shown)terminal rod members 16.

. embodyin strong ske eton frame for holding all of theor crack. The endportions of the. bars 18' are bent at substantially right angles to themain portion and are each provided with an I opening '19 therethroughwithin which is located a bushing 21 of a suitable refractoryelectric-insulating material, through which the rounded endportions ofthe rods 16 extcnd.--

End bars 22, of metal, have openings 23 extending laterallytherethrough, through which the bushings 21 may extend, the bars 22being so located as to operatively'enga'ge the turned-over end portionsof the bars 18. Washers 24c and nuts 25 are provided for each end of therod 16 to permit of securely clamping the bars 22 against theturned-over end portions of the respective bars '18, substantially asillustrated in Fig. 1 of the drawings thereby providing asupportingstructure ofskeleton formand of substantiall rectangular contour.

" -T e hereinbefore described method of preforming the resistor member12 brings both end portionsof, the resistor member at one end oftheheating-unit, substantially as'il- 'lustrated in Fig. 1 of the drawing,and'the clearance-allowed between the outside end of the end members 13and the inside of the bushings 21 'issufiicient at that end of theheating unit to permit of properly securing the ends of theresistormember to the re spective rods 16. As the rods 16 extend along the sideofthe assembled heating unit and beyond the skeleton frame structure,and as the rods 16 constitute terminal members for the heatingunit,'both terminals of the heating unit ex- .tend therebeyond at bothends thereof.

Extra nuts 26 are provided on the outer end of each of the rods 16topermit ofsuitably securing the ends of supply circuit to the respective;The device embodying my invention thus provides a relatively simple andcompact eating unit having a doublelayer winding of-"i'esistor material,whereby the capacity thereof is substantially doubled relatively to aheating'unit having j only. a single layer winding. Thehereinbeforedescribed construction further provides a heating unit a lelativelysimple and yet ends of sai nation, a relatively heavy resistor member,

preformed to comprise a plurality of substantially parallel-extending,return-bent, straight portions, a plurality of spaced sets of refractorymembers, of electric-insulating material, each having a plurality ofspaced pockets in one face thereof for receiving the return-bent parts.of said resistor member and having an opening extending longitudinallytherethrough, and a rod extending through the-openings in the refractorymembers of each set for supporting them in proper operative positions.

2. In an electric heating unit, in combination, a relatively heavyresistor member, preformed to comprise a plurality of substantiallyparallel-extending, return-bent, straight portions, a plurality ofspaced sets of refractory members, of electric-insulating material, eachhaving a plurality of.

spaced pockets in one face thereof for receiving the return-bent partsof said'resistor member andhaving an opening extending longitudinallytherethrough, and a rod extending through theopenings in the refractorymembers of each set for supportlng them in proper operative positions,each of said rods having one end of said resistor .member connectedthereto and serving as a terminal member for said heating unit.

3. In an electric heating unit, 1n combinat1on,a relatively heavyresistor member, preformed to' comprise a plurality of substantiallyparallelextending, return-bent, straight portions, a plurality of spacedsets of refractory members, of electric-insulat ing material, eachhaving a plurality, of

- spaced pockets in one face thereof for receiving thev return-bentparts of said resistor member and havingan opening extendinglongitudinally therethrough, a rod extending through the'openings in therefractory members of each set for supporting them in Lproper operativepositions and a skeleton frame, of metal, opcratively engaging the endsof said rods to hold them inproper" operative positions.

4; In an electric heating unit, in combination, a relativelyheavyresistor member, preformed tocomprise a plurality of substantiallyparallel-extending, return-bent, straightportions, a plurality of spacedsets of refractory members, of electric-insulating material, each havinga plurality of spaced pockets in one face thereof for receiving thereturn-bent parts of "said resistor member and having an openingextending longitudinally therethrough, a rod extend ing through theopenings in-"the refracto members of each set. for supporting them inproperv operative positions, and a skeleton metal frame havingsidemembers operativesaid refractory members andthe rods for holdingthem in proper 1y engagingi operative positions.

,5. In an electric heating unit, in combination, a relatively heavyresistor member, preformed to comprise a plurality of substantiallyparallel-extending, straight portions, a plurality of spaced sets ofrefractory members, of electric-insulatin'gmaterial, each having aplurality of spaced pockets in one face thereof for receiving thereturn-bent parts of said resisitor member and having an openingextending longitudinally therethrough, a rod extendmg through theopenings in the refractory'members of each set for supporting them inproper operative positions'and a skeleton metal frame having sidemembers interfitting' with said refractory members and operativclyengaging said rods to hold them in proper operative positions.

6. In an electric heating unit, in combination, a relatively heavy'resistor member, .preformed to comprise a plurality of substantiallyparallel-extending, return-bent, straight portions, a plurality ofspaced sets of refractory members, of electric-insulating material, eachhaving a plurality of spaced pockets in one face thereof for receivingthe return-bent parts of said resistor member and having an openingextending longitudinally therethrough, and a rod, of polygonalcross-section, extending through the openings in the refractory membersof each set for supporting them in abutting, alined position and forpreventing a turning movement thereof on said rod.

7. In an electric heating unit, tion, a relatively heavy resistormember, preformed to comprise a plurality of substantiallyparallel-extending, return-bent, straight portions, a plurality ofspaced sets of refractory members, of electric-insulating material, eachhaving a plurality of spaced pockets in one face thereof for receivingthe return-bent parts of said resistor member and having an openingextending longitudinally therethrough, and a plurality of substantiallyco-extensive members respectively extending through, and closelyadjacent to, each set of refractory members to hold them in properoperative positions.

8, In an electric heating unit, in combination. a relatively heavyresistor member,

return-bent,

in combina preformed to comprise a plurality of substantiallyparallel-extending, return-bent, straight portions, a plurality ofspacedsets of refractory members, of electric-insulating material, eachhaving a plurality of spaced pockets in one face thereof for receivingthe return-bent parts of said resistor member and. having an openingextending longitudinally therethrou'gh,,and a plurality of substantiallyco-extenslve elongated metal members, having intcrfitting ends, andrespectively extending through and closely adjacent to, each set of reractory members to hold them in proper operative positions.

9. In an electric heating unit, in combination, a relatively heavyresistor member, preformed to comprise'a' plurality of substantiallyparallel-extending, return-bent, straight portions, a plurality ofspaced sets of refractory members, of electric-insulating material, eachhaving a plurality of spaced pockets in one face thereof for receivingthe return-bent parts of said resistor member and having an openlngextending longi- .tudinally therethrough, a plurality of elongated metalmembers having interfitting ends and respectively extending through andclosely adjacent to, each set of refractory members, and end bar membersoperatively engaging said elongated members adj-acent to the endsthereof to constitute therewith a skeleton supporting frame, for saidrefractory members and said resistor member. 7

10. In an electric heating unit, the combination with a resistor memberpreformed to have a plurality of return-bent portions,

of a refractory lnsulating member having a longitudinal opening thereinand pockets in one face thereof for the upper returnbent portions of theresistor, a similar refractory insulating member for the lowerreturn-bent port-ions of the resistor, and a rod extending through eachof the refractory insulating members constituting a terminal andsupporting member for the unit.

In testimony whereof, I have hereunto subscribed my name this 21st dayof January 1924. Y

JAMES J. WOODSON.

